Endocrine Abstracts

Background: Pituitary Stalk Interruption Syndrome (PSIS) is a rare congenital anomaly affecting the pituitary gland with characteristic MRI findings of small or absent anterior pituitary gland, misplaced or absent posterior pituitary gland and very thin or interrupted pituitary stalk (1). Patients with PSIS often presents with signs and symptoms of either isolated growth hormone deficiency or multiple anterior pituitary hormone deficiency and symptoms differ according to age at diagnosis (2). We report a case of pituitary stalk interruption syndrome in a 22-year old Filipino male presenting with micropenis.

Case: A 22-year old Filipino male was referred to endocrinology service for evaluation of micropenis. His birth history was unremarkable. Developmental milestones were at par with age. Both parents and 3 siblings were healthy. On examination, his BP was 90/60 mmHg with a height of 139.7 cm, weight of 32 kg, with a eunuchoid proportion. Facial, axillary and pubic hair were absent. His testes were 1 ml in size, with a 1.5 cm-at-stretch penis. Laboratory findings showed: Total testosterone 0.11 ng/ml (NV: 2.80-8 ng/ml), FSH 0.18 mIU/ml (NV: 1.5-12.40 mIU/ml), LH < 0.100 mIU/ml (NV: 1.70-8.60 mIU/ml), FT4 8.63 pmol/l (12-22 pmol/l), TSH 6.17 uIU/ml (NV: 0.27-4.20 uIU/ml), IGF 1 13.23 ng/ml (120-388 ng/ml), Prolactin 191.40 mIU/l (NV: 86-324 mIU/l), Estradiol < 5 pg/ml (NV: 25.80-60.70 pg/ml), DHEAS 0.07 umol/l (NV: 6.50-14.60 umol/l). ACTH stimulation test was done, baseline cortisol was 78. 27 nmol/l (NV: 172-497 nmol/l), 30 minutes and 60 minutes post ACTH cortisol levels were 290 nmol/l and 60 minutes cortisol: 343. 20 nmol/l respectively indicating intact adrenal gland. His bone age was 14 years. Pituitary MRI results were consistent with pituitary stalk interruption syndrome.

Conclusion: Despite being a rare syndrome, pituitary stalk interruption syndrome should be one of the differential diagnosis in patients presenting with micropenis and short stature. Importance of early recognition of the disease is important because it associated with permanent hormonal deficiencies leading to significant morbidity and mortality.

References: 1. Gutch M, Kumar S, Razi SM, Saran S, Gupta KK. Pituitary stalk interruption syndrome: Case report of three cases with review of literature. Journal of Pediatric Neurosciences. 2014; 9(2):188-191. 2. El Chehadeh-Djebbar S, Callier P, Masurel-Paulet A, Bensignor C, Me´jean N, et al. (2011) 17q21.31 microdeletion in a patient with pituitary stalk interruption syndrome. Eur J Med Genet 54: 369–373